Dell Networking 2048, Reference Manual

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Port Monitor Commands
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Port Monitor Commands
Dell Networking N2000/N3000/N4000 Series Switches
Dell Networking switches allow the user to monitor traffic with an external
network analyzer. The external network analyzer can use any of the Ethernet
ports as a probe port. The probe port transmits a mirror copy of the traffic
being probed. Network traffic transmission is always disrupted whenever a
configuration change is made for port monitoring. Therefore, whenever port
monitoring is enabled, the probe port does not always forward traffic as a
normal port. When diagnosing problems, an operator should always check the
status of port monitoring.
The port monitoring feature allows the user to configure a single probe
session. A session consists of one destination or probe port and one or
multiple source ports. When a session is enabled, any traffic entering or
leaving the source ports of that session is copied (mirrored) onto the
corresponding destination port. A network traffic analyzer can be attached to
destination ports to analyze the traffic patterns of source ports.
A session is operationally active only if both a destination port and at least
one source port are configured. If neither is true, the session is inactive. A port
configured as a destination port acts as a mirroring port when the session is
operationally active. If it is not, the port acts as a normal port and participates
in all normal operation with respect to transmitting traffic.
Any Ethernet port may be configured as a source port.
Caveats:
• Platforms may behave unpredictably if an attempt is made to mirror a port
of greater speed than the probe port.
• Once configured, there is no network connectivity on the probe
(destination) port. The probe port does not forward any traffic and does
not receive any traffic. The probe tool attached to the probe port is unable
to ping the networking device or ping through the networking device, and
no device is able to ping the probe tool.
• ACL attributes redirect, mirror, log, rate-limit, assign-queue, time-range,
IGMP type, ICMP type, ICMP code, routing, fragments, and TCP
established are not supported when applied to a mirroring session.
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